1、当信息在一个队列中变成死信时，可以重新发送到DLX，绑定DLX的队列称为rabbitmq。
也叫死信队列。
2、常用于订单超时自动取消，会议预订提前提醒等等。
实例
importpika
importjson
importtime
credentials=pika.PlainCredentials('admin','admin')#mq用户名和密码
#虚拟队列需要指定参数virtual_host，如果是默认的可以不填。
connection=pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1',port=5672,credentials=credentials))
channel=connection.channel()
#声明消息队列，消息将在这个队列传递，如不存在，则创建
queue_name="delay_queue_a"
exchange='delay_exchange_a'
routing_key='delay_routing_key_a'
dead_letter_exchange='dead_exchange_a'#'amq.direct'#'dead_exchange_a'
dead_letter_routing_key='dead_letter_routing_key_a'#'dead_queue_a'#'dead_letter_routing_key_a'
arguments={
"x-message-ttl":5000,
'x-dead-letter-exchange':dead_letter_exchange,
'x-dead-letter-routing-key':dead_letter_routing_key
}
channel.confirm_delivery()
channel.exchange_declare(exchange=exchange,durable=True,exchange_type='direct')
result=channel.queue_declare(queue=queue_name,durable=False,arguments=arguments)
channel.queue_bind(exchange=exchange,queue=queue_name,routing_key=routing_key)
foriinrange(10):
message=json.dumps({'OrderId':i})
#向队列插入数值routing_key是队列名
channel.basic_publish(exchange=exchange,routing_key=routing_key,body=message,
properties=pika.BasicProperties(delivery_mode=2))
print(message)
time.sleep(1.5)
connection.close()
以上就是python rabbitmq的介绍，希望对大家有所帮助。更多Python学习指路：Python基础教程